Indirect driven propeller



Jan. 21, 1969 MULLER 3,422,905

INDIRECT DRIVEN PROPELLER Filed Feb. 16, 1967 IN V EN TOR. EQA/EST Ma 45/? United States Patent 1 Claim ABSTRACT OF THE DISCLOSURE The propeller is driven indirectly and involves differences of construction employing a flange for the accommodation of a hold-down bolt or bolts which are seen to establish connection between the propeller and shaft coupling, and is an object therefore of the invention.

The present invention relates generally to indirect driven propeller mechanisms and more particularly the invention improves the conventional existing marine propellers by:

(1) Propeller runs on outer stern tube and is driven by the propeller shaft which is running inside the stern tube;

(2) Propeller weight is carried by the inert hull structure through the stern tube (not hanging at the end of the powered propeller shaft);

(3) Propeller is driven through keys between propeller boss and propeller shaft coupling;

(4) Propeller boss diameter can be increased to permit eflicient installation of desired number of blades;

(5) Maximum efiiciency is obtained by low revolutions;

(6) There is no water flow and disturbance in the center of the propeller;

(7) The actual combined bending and torsion fatigues of the shaft are reduced to only torsion fatigue;

(8) The device of the invention enables the most efficient construction of the largest low speed propeller;

(9) This type of propeller will be the most efiicient with regard to a ships vibrations;

(10) The stern post and stern tube may be built to suit any load;

(11) The bushings, bearings and seals are of the conventional types.

An object therefore of the present invention is to provide an improved propeller for use in marine environments and in which the propeller is run on stem tubes.

The above and other objects and advantages of the invention will become apparent upon full consideration of the following detailed description and accompanying drawings in which:

FIGURE 1 is a side elevation view shown partly in cross-section of the indirect driven marine propeller running on a stern tube in accordance with the preferred embodiment of the present invention; and

FIGURE 2 is a cross-sectional view taken along lines 2-2 of FIG. 1.

Referring now to the drawings, there is shown a propeller 10 mounted from a center line 12, the propeller shaft having a driving coupling means 16 which is either solid or of removable nature. From the stern tube or driving coupling 16, there is mounted the propeller 10 which is a propeller case complete or may be prefabricated and is mounted from a propeller bushing 20 and from a stern tube outer sleeve 22.

The stem tube 26 is shown secured in a stern post 28 for carrying the propeller load, the stern being cast or prefabricated and adapted for holding the after structure.

The stem tube is retained in position by a securing nut 30. A rope guard 32 is disposed over and around the stern tube securing nut 30, as well as over and peripheral of the propeller bearing oil seal 34.

Between the propeller 10 and the shaft coupling 16, there is mounted holding-down bolts 38 which pass through an opening 40 in the flanged stern portion of the propeller shaft driving coupling 16.

A stern tube inner bushing 44 is disposed in mating relation between the driving coupling 16 and the stern tube 26, and a propeller hub cover 48 encases the holding-down bolts 38 and the adjustment nuts 50 on the bolt 38.

There is provided a securing ring 52, 52 for the sleeve stern tube outer sleeve 22 and the stern tube inner bushing 44. There are driving keys 56 which are machined and placed in the propeller 10 and the driving coupling 16 to maintain a fixed relation therebetween, as is a wellknown expedient.

Additional embodiments of the invention in this specification will occur to others and therefore it is intended that the scope of the invention be limited only by the appended claims and not by the embodiment described hereinabove. Accordingly reference should be made to the following claims in determining the full scope of the invention.

What is claimed is:

1. An indirect driven marine propeller running over a stern tube, comprising a propeller shaft for mounting a propeller having a hub, blades and shaft arranged thereon with a driving coupling for a propeller, a stern tube secured to a stern post and adapted for carrying the propeller load, a propeller bushing and a stern tube outer sleeve interposed between the propeller and the stern tube, said driving coupling having an end flange with a plurality of apertures for receiving a hold-down bolt in each of said apertures for securing said propeller to said driving coupling, and a stern tube inner bushing disposed between said driving coupling and said stern tube, said holdingdown bolts being disposed between said propeller and said driving coupling and having tightening nuts, a driving key being machined in the propeller and said coupling, a stern tube securing nut disposed on the stern tube, and a rope guard peripherally mounted about said stern tube securing nut.

References Cited UNITED STATES PATENTS 1,035,404 8/1912 Arnold -173 2,272,128 2/ 1942 Osbourne 170-16023 2,987,123 6/1961 Liaaen 170-16023 3,051,249 8/1962 Dirlik 170-16023 X 3,087,553 4/1963 Kostyun 170-13528 EVERETTE A. POWELL, Jr., Primary Examiner.

U.S. Cl. X.R. 170-159 

